Reductions in glucose among postmenopausal women who use and do not use estrogen therapy

Menopausal hormone therapy decreases the likelihood of diabetes development in peri‑menopausal individuals with prediabetes

BACKGROUND

The influence of menopausal hormone therapy (MHT) on the probability of developing diabetes mellitus in individuals with prediabetes remains uncertain.

METHODS

This retrospective cohort study, utilizing the TriNetX U.S. Collaborative Network, investigated cohorts, implemented propensity score matching, and analyzed outcomes associated with diabetes mellitus. The study focused on individuals aged 46-60 with prediabetes prior to menopause, categorizing them into MHT and non-MHT groups. Further stratified analyses, including variables such as age and race, were conducted to thoroughly examine potential variations in outcomes.

RESULTS

The study involved 6566 individuals (MHT and non-MHT), with propensity score matching ensuring balanced cohorts. Over a 20-year follow-up, the MHT group demonstrated a lower incidence of diabetes mellitus compared to the non- MHT group, with a Hazard Ratio of 0.693 (95 % CI: 0.577, 0.832). Stratified analyses revealed age-specific nuances, with significant protective effects in individuals aged 46-50 and 55-60. Additionally, ethnicity played a role, with MHT demonstrating significant benefits in White individuals but not in the Black or Asian populations. BMI analysis indicated a significant risk reduction with MHT in individuals with BMI less than or equal to 24.9 and 25-29.9 kg/m 2, but not in those with BMI greater than or equal to 30 kg/m 2.

CONCLUSION

In our study, we demonstrate a sustained 20-year decrease in the risk of diabetes among premenopausal individuals with prediabetes who undergo menopausal hormone therapy.

Progenies of gestational diabetes mellitus exhibit sex disparity in metabolism after respective therapies of insulin, glibenclamide, and metformin in dams during pregnancy

BACKGROUND

The aim of this study was to compare the sex-dependent intergenerational effects of insulin, glibenclamide, and metformin on glucose and lipid metabolism in the offspring born to GDM mice.

METHODS

The murine GDM was induced by high fat diet. The offspring were grouped based on the treatments in maternal mice. ITT and GTT were performed at 4th and 8th weeks of age, respectively. Serum levels of TC, TG, HDL-C, and LDL-C plus hepatic levels of TG and TC, were respectively determined by enzymatic kits. Western blotting was conducted to detect related proteins in the livers from offspring.

RESULTS

The dyslipidaemia, hepatic lipid abnormality, and insulin insensitivity caused by GDM were persistently normalised in male adult offspring by the respective therapies of insulin, glibenclamide, and metformin during maternal pregnancy. Specifically, the decreases in plasma TC, TG, and LDL-C levels (29%, 37.8%, and 57.7%, respectively, p ˂ .05) and in hepatic lipid contents (TC 31.3% and TG 39.2%, p ˂ .05), the increases in hepatic phosphorylation levels of AKT, CPT1A, PPAR-α, and PPAR-γ (57.1%, 91.7%, 68%, and 173.3%, respectively, p ˂ .05) and the inhibition of G6Pase, PEPCK, and HMGCS1 (35.7%, 68.8%, and 77.3% respectively, p ˂ .05) were still observed in the male offspring born to treated GDM mice from 4th to 8th week of age. Unexpectedly, the aforementioned parameters in female progenies in different groups were not significantly changed compared with controls.

CONCLUSIONS

Respective treatments in GDM mice during pregnancy with insulin, glibenclamide, and metformin have the long-term persistent effects in male offspring, while female progenies born to untreated dams showed an autonomous inhibition of intergenerational relay of glucose and lipid dysregulation. Our current findings may imply a sex-dependent strategy of medical care for GDM mothers and their offspring.NoveltiesRespective interventions of insulin, glibenclamide, and metformin on dams exerted the persisted effects on male progenies.Therapies of three drugs on dams had the similarly improved effects in offspring.Female offspring autonomously corrected their dysregulated glucose-lipid metabolism caused by gestational diabetes mellitus (GDM) in dams.

Correlates of serum estradiol concentration among postmenopausal women in Ilorin, North-Central Nigeria

OBJECTIVES

There are limited data on the associated factors of circulating endogenous estradiol among Nigerian postmenopausal women. The main objective of this study is to assess the relationship between serum estradiol levels and some menstrual, clinical, and sociodemographic factors in postmenopausal women attending a family medicine clinic in Nigeria.

METHODS

This was a hospital-based cross-sectional study involving 372 postmenopausal women. Sociodemographic, menstrual, and clinical data of the participants were collected, and their serum estradiol concentrations were assayed. The collected data were analyzed using IBM SPSS version 21 statistical software. A χ2 test of association and logistic regression analysis were done to identify significant correlates of serum estradiol concentration among the participants.

RESULTS

The mean ages at menarche and menopause among the participants were 15.6 and 48.1 years respectively. Approximately half of them (51.1%) were receiving chronic medical care for systemic hypertension and/or diabetes. The mean estradiol concentration of the participants in the study was 20.69 pg/mL. The participants' marital status and clinical presentation pattern (chronic vs others) were found to have statistically significant associations with their serum estradiol concentration; P = 0.048 and P = 0.001, respectively. Logistic regression analysis revealed that only the clinical presentation pattern had a significant relationship with serum estradiol concentration among the participants (P = 0.002).

CONCLUSION

Of all the studied factors, the only significant correlate of low serum estradiol concentration found in this study was chronic medical care presentation for hypertension and/or diabetes.

Estradiol (E2) Improves Glucose-Stimulated Insulin Secretion and Stabilizes GDM Progression in a Prediabetic Mouse Model

Female New Zealand obese (NZO) mice are an established model of preconceptional (pc.) prediabetes that progresses as gestational diabetes mellitus (GDM) during gestation. It is known that NZO mice show improvement in insulin sensitivity and glucose-stimulated insulin secretion (GSIS) during gestation in vivo. The latter is no longer detectable in ex vivo perifusion experiments in isolated islets of Langerhans, suggesting a modulation by extrapancreatic factors. Here, we demonstrated that plasma 17β-estradiol (E2) levels increased markedly in NZO mice during gestation. The aim of this work was to determine whether these increased E2 levels are responsible for the improvement in metabolism during gestation. To achieve this goal, we examined its effects in isolated islets and primary hepatocytes of both NZO and metabolically healthy NMRI mice. E2 increased GSIS in the islets of both strains significantly. Hepatic glucose production (HGP) failed to be decreased by insulin in NZO hepatocytes but was reduced by E2 in both strains. Hepatocytes of pregnant NZO mice showed significantly lower glucose uptake (HGU) compared with NMRI controls, whereby E2 stimulation diminished this difference. Hepatocytes of pregnant NZO showed reduced glycogen content, increased cyclic adenosine monophosphate (cAMP) levels, and reduced AKT activation. These differences were abolished after E2 stimulation. In conclusion, our data indicate that E2 stabilizes and prevents deterioration of the metabolic state of the prediabetic NZO mice. E2 particularly increases GSIS and improves hepatic glucose utilization to a lower extent.

Effects of estradiol supplementation on the brain transcriptome of old rhesus macaques maintained on an obesogenic diet

Obesity, the cessation of ovarian steroids with menopause, and age are risk factors for mood disorders, dementia, and Alzheimer's disease (AD). However, immediate hormone therapy (HT) after menopause may have beneficial effects in different brain regions involved in memory and cognition. To more closely replicate the age, endocrine, and metabolic environment of obese postmenopausal women, either on or off HT, middle-aged female rhesus macaques were ovariectomized/hysterectomized (OvH) and maintained on a high-fat, high-sugar, obesogenic Western-style diet (WSD) for 30 months; half of the animals received HT immediately after OvH and half served as placebo controls. RNAseq of the occipital (OC) and prefrontal cortex (PFC), hippocampus (HIP), and amygdala (AMG) identified 293, 379, 505, and 4993 differentially expressed genes (DEGs), respectively. Pathway enrichment analysis identified an activation of neuroinflammation in OC and HIP, but an inhibition in the AMG with HT. Synaptogenesis, circadian rhythm, mitochondrial dysfunction, mTOR, glutamate, serotonin, GABA, dopamine, epinephrine/norepinephrine, glucocorticoid receptor signaling, neuronal NOS, and amyloid processing were exclusively enriched in AMG. As compared to the placebo control group, most of these signaling pathways are downregulated after HT, suggesting a protective effect of HT in OvH females under a WSD. Overall, our results suggest that a chronic obesogenic diet may induce a wide range of alterations in multiple signaling pathways that are linked to age-associated brain pathology and dementia. In these individuals, HT seems to have a protective effect against neuroinflammation, amyloid beta depositions, and tau tangle formation.

Sex-specific expression mechanism of hepatic estrogen inactivating enzyme and transporters in diabetic women

Circulating estrogens levels significantly decrease in menopause and levels off in postmenopausal women. Accordingly, the liver represses levels of enzymes and membrane transporters, thereby decreasing capability of inactivating and excreting estrogens. Women increasingly develop type 2 diabetes during or after menopause. Estrogens are known to promote liver diseases in these women. Here, we have found that the estrogen inactivating sulfotransferase (SULT1E1) and an ATP-binding cassette subfamily G member 2 (ABCG2), a gene encoding breast cancer resistance protein that exports sulfated estrogens, increased their expression levels in diabetic women but not men. For the sulfotransferase gene, phosphorylated nuclear receptors ERα and RORα, at Ser212 and Ser100, respectively, bind their response elements to activate the SULT1E1 promoter in women. This coordinated increase in estrogen inactivation and excretion, and the phosphorylated nuclear receptor-mediated gene activation could be a defense mechanism against toxicities of estrogens through inactivation and excretion in the livers of women.

Estrogen Improves Insulin Sensitivity and Suppresses Gluconeogenesis via the Transcription Factor Foxo1

Premenopausal women exhibit enhanced insulin sensitivity and reduced incidence of type 2 diabetes (T2D) compared with age-matched men, but this advantage disappears after menopause with disrupted glucose homeostasis, in part owing to a reduction in circulating 17β-estradiol (E₂). Fasting hyperglycemia is a hallmark of T2D derived largely from dysregulation of hepatic glucose production (HGP), in which Foxo1 plays a central role in the regulation of gluconeogenesis. Here, we investigated the action of E₂ on glucose homeostasis in male and ovariectomized (OVX) female control and liver-specific Foxo1 knockout (L-F1KO) mice and sought to understand the mechanism by which E₂ regulates gluconeogenesis via an interaction with hepatic Foxo1. In both male and OVX female control mice, subcutaneous E₂ implant improved insulin sensitivity and suppressed gluconeogenesis; however, these effects of E₂ were abolished in L-F1KO mice of both sexes. In our use of mouse primary hepatocytes, E₂ suppressed HGP and gluconeogenesis in hepatocytes from control mice but failed in hepatocytes from L-F1KO mice, suggesting that Foxo1 is required for E₂ action on the suppression of gluconeogenesis. We further demonstrated that E₂ suppresses hepatic gluconeogenesis through activation of estrogen receptor (ER)α-phosphoinositide 3-kinase-Akt-Foxo1 signaling, which can be independent of insulin receptor substrates 1 and 2 (Irs1 and Irs2), revealing an important mechanism for E₂ in the regulation of glucose homeostasis. These results may help explain why premenopausal women have lower incidence of T2D than age-matched men and suggest that targeting ERα can be a potential approach to modulate glucose metabolism and prevent diabetes.

A semiparametric imputation approach for regression with censored covariate with application to an AMD progression study

This research is motivated by studying the progression of age-related macular degeneration where both a covariate and the response variable are subject to censoring. We develop a general framework to handle regression with censored covariate where the response can be different types and the censoring can be random or subject to (constant) detection limits. Multiple imputation is a popular technique to handle missing data that requires compatibility between the imputation model and the substantive model to obtain valid estimates. With censored covariate, we propose a novel multiple imputation-based approach, namely, the semiparametric two-step importance sampling imputation (STISI) method, to impute the censored covariate. Specifically, STISI imputes the missing covariate from a semiparametric accelerated failure time model conditional on fully observed covariates (Step 1) with the acceptance probability derived from the substantive model (Step 2). The 2-step procedure automatically ensures compatibility and takes full advantage of the relaxed semiparametric assumption in the imputation. Extensive simulations demonstrate that the STISI method yields valid estimates in all scenarios and outperforms some existing methods that are commonly used in practice. We apply STISI on data from the Age-related Eye Disease Study, to investigate the association between the progression time of the less severe eye and that of the more severe eye. We also illustrate the method by analyzing the urine arsenic data for patients from National Health and Nutrition Examination Survey (2003-2004) where the response is binary and 1 covariate is subject to detection limit.

Menopause, hormone therapy and diabetes

Over the past three decades, the prevalence of diabetes has increased four-fold. Coupled with the global obesity epidemic and aging of the world's population, a perfect metabolic storm is brewing. The influence of menopause and exogenous estrogen and progestogens must be included in this equation. In this review, criteria for diagnosing diabetes and recommendations for screening are described. The reported effects of menopause on diabetes risk in healthy women are reviewed as well as the relationship between established diabetes and the timing of menopause. The effects of menopausal hormone therapies (MHT) on glucose control in women with diabetes and the effect of MHT on diabetes risk in menopausal women without diabetes are described. Evidence-based strategies to prevent diabetes in midlife women are highlighted. The augmenting effect of diabetes on chronic health concerns of aging women, such as cardiovascular disease, osteoporosis, and cancer, along with current recommendations for screening and prevention are presented. Given the current demographics of today's world, the content of this review may apply to as many as one-third of the average practitioner's postmenopausal patient population.

Endogenous sex steroid hormones and glucose in a South-Asian population without diabetes: the Metabolic Syndrome and Atherosclerosis in South-Asians Living in America pilot study

AIMS

To examine the associations between endogenous sex steroid hormones (oestradiol, testosterone and sex hormone-binding globulin) with diabetes risk in a South-Asian population living in the USA.

METHODS

We used data from the Metabolic Syndrome and Atherosclerosis in South-Asians Living in America pilot study. The analytical sample included 60 women and 45 men of Asian Indian origin living in the San Francisco Bay Area, who were free from diabetes and cardiovascular disease and did not use exogenous sex steroids. Sex steroid hormone levels were assessed by validated conventional radioimmunoassays, and visceral and hepatic adiposity were assessed by computed tomography. We used multivariable regression to examine the association between endogenous sex steroid hormone levels (log-transformed) and fasting glucose and 2-h glucose levels in a series of sex-stratified models adjusted for age, waist circumference, visceral and hepatic adiposity, and insulin resistance.

RESULTS

In age-adjusted models, lower levels of sex hormone-binding globulin (β = -0.18, 95% CI -0.30, -0.06) and higher levels of free testosterone (β = 0.14, 95% CI 0.02, 0.26) were associated with elevated fasting glucose levels in South-Asian women, whereas lower levels of sex hormone-binding globulin (β = -0.14, 95% CI -0.26, -0.02) and lower levels of total testosterone (β = -0.12, 95% CI -0.24, 0.00) were associated with elevated fasting glucose levels in South-Asian men. Adjustment for waist circumference, visceral adiposity and insulin resistance attenuated most of these associations, while adjustment for hepatic adiposity strengthened some of the observed associations. Similar results were found for 2-h glucose levels.

CONCLUSIONS

Results were consistent with previous research, which suggests that endogenous sex steroid hormones are a risk factor for diabetes across multiple race/ethnic groups. Additional studies are needed to determine whether visceral fat is a mediator or confounder of associations between sex steroid hormone and glucose levels.

Does hormone therapy affect blood pressure changes in the Diabetes Prevention Program?

OBJECTIVE

This study aims to examine whether blood pressure reductions differ by estrogen use among overweight glucose-intolerant women.

METHODS

We conducted a secondary analysis of Diabetes Prevention Program postmenopausal participants who used oral estrogen with or without progestogen at baseline and 1-year follow-up (n = 324) versus those who did not use oral estrogen with or without progestogen at either time point (n = 382). Changes in systolic blood pressure (SBP) and diastolic blood pressure (DBP) were examined by randomization arm (intensive lifestyle change [ILS], metformin 850 mg twice daily, or placebo). Associations between changes in blood pressure and changes in sex hormone-binding globulin, estradiol, testosterone, and dehydroepiandrosterone were also examined.

RESULTS

Estrogen users and nonusers had similar prevalences of baseline hypertension (33% vs 34%, P = 0.82) and use of blood pressure medications at baseline (P = 0.25) and on follow-up (P = 0.10). Estrogen users and nonusers randomized to ILS had similar decreases in SBP (-3.3 vs -4.7 mm Hg, P = 0.45) and DBP (-3.1 vs -4.7 mm Hg, P = 0.16). Among estrogen users, women randomized to ILS had significant declines in SBP (P = 0.016) and DBP (P = 0.009) versus placebo. Among nonusers, women randomized to ILS had significant declines in DBP (P = 0.001) versus placebo, but declines in SBP were not significant (P = 0.11). Metformin was not associated with blood pressure reductions versus placebo regardless of estrogen therapy. Blood pressure changes were not associated with changes in sex hormones regardless of estrogen therapy.

CONCLUSIONS

Among overweight women with dysglycemia, the magnitude of blood pressure reductions after ILS is unrelated to postmenopausal estrogen use.

Endogenous sex hormones, metabolic syndrome, and diabetes in men and women

Endogenous sex hormones predict impairments of glucose regulation. Cross-sectional studies suggest that lower levels of testosterone in men and higher levels in women increase risk of metabolic syndrome and diabetes, whereas lower levels of sex hormone binding globulin in both men and women increase risk of metabolic syndrome and diabetes. In a systematic review, we summarize existing longitudinal studies, which suggest similar patterns. However, these studies are often limited to a single sex steroid measure. Whether these associations are primarily a marker of adiposity, and whether these associations differ between younger eugonadal vs older hypogonadal adults is also uncertain. The impact of exogenous sex steroid therapy may not reflect relationships between sex hormones and impaired glucose regulation that occur without supplementation. Therefore, examination of endogenous sex steroid trajectories and obesity trajectories within individuals might aid our understanding of how sex steroids contribute to glucose regulation.

Sex steroid levels and response to weight loss interventions among postmenopausal women in the diabetes prevention program

OBJECTIVES

To examine whether estrogen use potentiates weight loss interventions via sex steroid levels and whether endogenous sex steroid levels predict response to weight loss interventions among women not using estrogen.

METHODS

The Diabetes Prevention Program randomized overweight or obese dysglycemic participants to lifestyle change with the goals of weight reduction of >7% of initial weight and 150 minutes per week of exercise, metformin, or placebo. In this secondary analysis, we examined sex steroid levels and reductions in weight and waist circumference (WC) among postmenopausal women using (n = 324) and not using (n = 382) oral estrogen.

RESULTS

Estrogen users and nonusers randomized to lifestyle change and metformin both lost significant amounts of weight compared to placebo. Reductions in weight and WC over 1 year associated with randomization arm were not associated with baseline sex steroid levels among estrogen users or nonusers.

CONCLUSIONS

Among estrogen users, baseline sex steroids were not associated with reductions in weight or WC, suggesting that exogenous estrogen does not potentiate weight loss by altering sex steroids. Among nonestrogen users, baseline sex steroids were not associated with reductions in weight or WC.

The association of elective hormone therapy with changes in lipids among glucose intolerant postmenopausal women in the diabetes prevention program

OBJECTIVE

It is unclear how lipids change in response to lifestyle modification or metformin among postmenopausal glucose intolerant women using and not using hormone therapy (HT). We examined the one-year changes in lipids among postmenopausal, prediabetic women in the Diabetes Prevention Program (DPP), and whether changes were mediated by sex hormones.

MATERIALS/METHODS

We performed a secondary analysis of a randomized controlled trial of 342 women who used HT at baseline and year 1 and 382 women who did not use HT at either time point. Interventions included intensive lifestyle (ILS) with goals of weight reduction of at least 7% of initial weight and 150 minutes per week of moderate intensity exercise, or metformin or placebo administered 850 mg up to twice a day. Women were not randomized to HT. Main outcome measures were changes between baseline and study year 1 in low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and triglycerides.

RESULTS

Compared to placebo, both ILS and metformin significantly reduced LDL-C and raised HDL-C among HT users, changes partially explained by change in estradiol and testosterone but independent of changes in waist circumference and 1/fasting insulin. In contrast, DPP interventions had no effect on LDL-C and HDL-C among non-HT users. ILS significantly lowered triglycerides among non-users but did not significantly change triglycerides among HT users. Metformin did not significantly change triglycerides among non-users but increased triglycerides among HT users.

CONCLUSIONS

The beneficial effects of ILS and metformin on lowering LDL-C and raising HDL-C differ depending upon concurrent HT use.

Racial/ethnic differences in sex hormone levels among postmenopausal women in the diabetes prevention program

CONTEXT

Sex hormones may differ by race/ethnicity in postmenopausal women. Whether racial/ethnic differences also exist among those who are overweight and glucose intolerant is not clear.

OBJECTIVES

The objective of the study was to compare sex hormones by race/ethnicity [non-Hispanic white (NHW), Hispanic, African-American (AA)] in overweight, glucose-intolerant, postmenopausal women.

DESIGN

This was a secondary analysis of a randomized controlled trial.

PARTICIPANTS

Participants included postmenopausal glucose-intolerant women participating in the Diabetes Prevention Program.

INTERVENTIONS

Interventions included intensive lifestyle modification (consisting of diet and physical activity) or metformin 850 mg twice a day vs. placebo.

MAIN OUTCOME MEASURES

Baseline levels and 1-yr intervention-related changes in SHBG, total and bioavailable estradiol (E2), total and bioavailable testosterone, and dehydroepiandrosterone were measured.

RESULTS

At baseline, among women not using estrogen (n = 370), NHW had higher total and bioavailable E2 and testosterone levels than Hispanics independent of age, type of menopause, waist circumference, alcohol intake, and current smoking. NHW also had higher levels of bioavailable E2 and lower levels of SHBG than AA. At baseline, among estrogen users (n = 310), NHW had higher total and bioavailable E2 than Hispanics and higher levels of SHBG than AA after adjustment. At 1 yr, among women not using estrogen, NHW had larger declines in total E2 and bioavailable E2 levels than AA after adjustment for the above covariates, changes in waist circumference, and randomization arm. At 1 yr, among estrogen users, sex hormone changes did not differ by race/ethnicity.

CONCLUSIONS

Among postmenopausal women, there were significant race/ethnicity differences in baseline sex hormones and changes in sex hormones.